Well conductor perforating gun



March 25, 1952 WELL CONDUCTOR PERFORATING GUN Filed Aug. 12, 1946 /9 0 ELI w. R. ATWOOD 2,590,366

4 Sheets-Sheet 1 W ILMERTH R. ATWOO D 4 INVENTOR..

ATTORNEYS March 25,1952 w. R. ATWOOD 2,590,356

WELL CONDUCTOR PERFORATING GUN Filed Au 12 1946 4 Sheets-Sheet 2 WILMERTH R ATWOOD INVENTOR.

- aygg TTORNEYS March 25, 1952 ,w. R. ATWOOD WELL CONDUCTOR PERFORATING GUN 4 Sheets-Sheet 3 Filed Aug. 12, 1946 WLMERTH A T1 0 R m: Y

Patented Mar. 25, 1952 WELL CONDUCTOR PERFORATING GUN Wilmerth R. Atwood, Odessa, Tex.

Application August 12, 1946, Serial No. 689,935

8 Claims; (01. 164-0.5)

This invention relates to new and useful improvements in well casing or pipe perforating guns.

It is one object of this invention to provide an improved well pipe or casing perforating gun which is simple and positive in action, and which insures proper perforation of the well casing or pipe in the desired manner.

An important object of the invention is to provide an improved well pipe or casing perforating gun in which the projectiles and powder charges along with the allied elements, may be readily removed and installed or adjustments made at the well site, where by return of the perforating gun to a servicing shop for minor adjustments or for reloading is not required.

Another important object of the invention is to provide an improved well pipe or casing perforating gun which may be unloaded from the rearward side of the gun chambers, so that a person working on the gun need not be in a position directly in the path of the projectile while unloading that particular gun unit.

Yet another object of the invention is to provide an improved well pipe or casing perforating gun wherein means are provided for disassembly of the gun elements without exposure and endangering of personnel, said means being effective to allow removal of the powder charge and/or the projectile; and wherein modifications may be provided to allow removal of the projectile chamber or sleeve and/or the barrel.

Still another object of the invention is to provide an improved well casing or pipe perforating gun wherein means are provided for conducting a propagated flame to and around the several gun elements aand powder chambers, which means is efiective to allow one powder charge to detonate others in the event of partial failure of the propagated flame so that mis-fires are substantially eliminated.

A further object of the invention is to provide an improved well casing or pipe perforating gun in which means are supplied for preventing the formation of burrs arround the'openings perforated in the casing or pipe by the projectile, said means being adapted to be carried with the projectile in its trajectory to remove effectively or prevent the formation of any burrs that would normally be formed by the projectile as it penetrates the well casing or pipe.

Still another object of the invention is to provide. an improved well casing or pipe. perforating gun wherein means are provided for effectively sealing off the projectile and powder cham- The invention will be more readily understood.

from a reading of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein: Fig. 1 is a longitudinal, vertical, sectional view showing a well casing or pipe perforating gun constructed in accordance with the invention,

Fig. 2 is an enlarged, horizontal, cross-sectional view taken on the line 2--2 of Fig. 1,

Fig. 3 is an enlarged, fragmentary, vertical, sectional view taken on the line 33 of Fig. 1, Fig. 4 is an enlarged, vertical, sectional view of the detonating unit,

Fig. 5 is an enlarged view, partly in elevation. and partly in section, of the projectile and the associated sealing plate structure, 7,

Fig. 6 is an enlarged, isometric view of the projectile,

Fig. 7 is a longitudinal, vertical, sectional view of a modified form of the invention, adapted for use for electrical detonation and operation,

Fig. 8 is an enlarged, vertical, sectional view of one of. the gun units,

Fig. 9 is an enlarged, horizontal, cross-sectional view taken on the line 9-9 of Fig. 7, a

Fig. 10 is an enlarged, vertical, sectional View taken on the line l0l9 of Fig. 8, r

Fig. 11 is an enlarged, horizontal, cross-sec-- tional view of a modified form of the ment, and

Fig. 12 is an enlarged, horizontal, cross-secgun eletional view of an additional modified form of the gun element.

In the drawings, the numeral Ill designates a well casing or pipe perforating gun constructed in accordance with this invention. understood that the term casing as applied hereafter to the gun is intended to cover casing,

pipe, or any kind of a well fluidconductor. l-he gun lil is adapted to be lowered into a wellbore It is to. be

by suitable means I4 which may be of any desirable form of rope socket, or joint, customarily used in making such connections.

A tapered, screw-threaded pin I5 is formed upon the lower end of the head I3, and an axial bore or passage I6 extends through the head. The bore I6 is reduced at its lower end to form a restricted passage IT, and a circular recess I8 is provided in the extreme lower end of the pin I5 in axial alinement with the bore I6 and passage II. The electrical conductor I2 carried by the cable extends downwardly from the retaining or securing means I4, through the bore I6 and the passage II, the conductor having a snug fit within the latter passage. The conductor terminates within the recess I8 for purposes to be set out hereinafter.

A tool-joint or sub l9 depends from the head I3 by means of a screw-threaded box 29 formed upon the upper end of the sub, and which engages the screw-threaded pin I5. The sub I9 is substantially equal in diameter to the head I3, so that a substantially continuous external, cylindrical surface is provided by the joining of the two elements. The sub is formed with an axial bore or conduit 2| extending throughout the length of the sub, said bore being enlarged at its upper end and screw-threaded to receive a screw-threaded bushing 22. The bushing 22 is tubular and provided with an enlarged head 23 which engages within the recess I8 and rests upon the bottom of the box and in snug engagement therewith. A longitudinal bore 24 extends axially of the bushing and receives an electrical detonating cap 25, (Fig. 4) which may be of any desirable type or construction. The cap 25 is provided with the usual flanged base 26 which is engaged between the bottom of the recess I8 and the enlarged head 23 of the bushing, whereby the cap is secured in place within the bore 24. The electrical conductor or cable I2 is provided with the usual conducting means (not shown) for establishing contact with the base of the shaft for detonating the latter by means of an electrical charge or current.

The lower end of the bore 24 is screw-threaded to receive a valve seat 21, positioned near the medial portion of the bore and adapted to be engaged by a valve ball 28. A ball-retaining collar 29 is positioned in the extreme lower end of the screw-threaded portion of the bore 24, and has its upper end conical in shape and formed at the apex-with a concave ball rest 30. A bore or passage 3| extends upwardly within the ball-retaining member 29, terminating short of the upper end thereof, while lateral ports 32 directed upwardly and outwardly at an angle, communicate between the passage 3| and the bore 24 beneath the ball rest 30. Thus, under normal conditions, the valve ball 28 will be positioned, due to gravity, upon the ball rest 39, and unimpeded communication is provided from the cap 25 downwardly through the valve seat 21, the ports 32, and the passage 3| to the axial bore of the passage 2| of the sub I9.

As will be seen from the operation of the gun, when it is fired, a back pressure is exerted The gun I0 includes a head upwardly through the bore 2|. The effect of this pressure is to pick up the valve ball 28, and seat it against the valve seat 21, thereby preventing escape and loss of pressure within the gun body.

A reduced screw-threaded pin 33 is formed upon the lower end of the sub I9, and engages within a screw-threaded box 34 formed upon the upper end of a cylindrical gun body 35. The gun body 35 is substantially equal in diameter to the sub I9 and the head I3 to provide a continuous exterior surface, and is formed with a reduced screw-threaded pin 36 upon its lower end to carry additional gun bodies 36 similar to the body 35.

An axial bore or conduit 31, similar to the bore 2|, extends longitudinally of the body 35, the bOre 31 being enlarged and screw-threaded at its upper end to form a box 38 similar to that formed in the upper end of the sub i9, and adapted to receive the bushing 22. The box 38 is provided for use in instances where it is not desired to incorporate the sub I9 into the gun unit. In such an instance, the bushing 22 and cap 25 would be mounted within the box 38, and the pin I5 of the head I3 engaged within the box 34 carried by the gun body 35. Thus the utilization of the sub I9 is optional and dependent upon the operating conditions under which the gun is to be used.

The gun body is provided with a plurality of gun elements 39, and it is pointed out, that although only two elements are shown in the drawings, any desirable number may be utilized. In addition, any desirable number of gun bodies 36, similar to the body 35, and carrying any suitable number of gun elements, similar to the elements 39, may be incorporated into the unitary well conductor perforating gun. This feature lends great flexibility to the gun and to the usage to which it may be put, since gun elements may be combined in any desirable number so as to be particularly adapted to the perforating operation at hand.

Each of the gun elements 39 includes a screwthreaded cylindrical box 40 formed in the outer wall of the gun body at one side thereof, and having its axis perpendicular to the longitudinal axis of the gun body. A similar, shallower box 4| is provided in the outer wall of the gun body diametrically opposite to the box 46 and in axial alinement therewith. The outer portion 42 of the box 4| is screw-threaded, while the inner portion 43 is reduced in diameter to form a powder chamber 44. A tapered bore extends between the chamber 44 and the box 40, the bore 45 intersecting the longitudinal bore 31 of the gun body, and having its larger end directed toward the box 40. A tapered or conical sleeve 46 has a snug fit within the tapered bore 45, and terminates flush with the bottoms of the chamber 44 and the box 49. A cylindrical bore 41 extends axially of the sleeve 46 and is adapted to receive in snug sliding engagement, a bullet or projectile 48. An annular internal groove 49, rectangular in cross-section, is formed in the medial portion of the tapered bore 45 in vertical alinement with the bore 31 of the gun body, and a complementary annular groove 56 is formed upon the external surface of the tapered sleeve 46, the groove being positioned medially of the sleeve so as to register with the groove 49. The bore 31 communicates with the grooves 49 and 50 above and below the sleeve 46, so that a continuous passage is provided through the bore 31 and around the sleeve.

A plurality of radial ports 5| extend inwardly through the wall of the sleeve from the groove 50 to the bore 41, and a groove 52, similar to the roove 49, is formed in the wall of the bore 49 so as to encircle the bore and be in alinement with the ports 5 I. Communication is thus establishedbetween the groove 59 and the groove 52. An internal, longitudinal groove 50' extends from the groove 52 to the smaller end of the sleeve along the wall of its bore 41.

The projectile 48 is reduced at its medial portion to form an annular groove 53 encircling the body of the projectile. The projectile is of the usual type, being cylindrical in configuration, and having a relatively pointed nose for facilitating penetration of the well casing or casings. A longitudinal groove 54 similar to the groove is formed in the surface of the bullet or projectile and extends rearwardly from the groove 53 to the extreme rearward end of the projectile. In this manner, a continuous passageway is provided from the bore 31- through the grooves 49 and 59', the ports 5|, the grooves 52 and 53, and the grooves 54 and 50 to a point adjacent the rearward end of the projectile, which is contiguous to the powder chamber 44.

The sleeve 4Bis provided at its smaller end with an axial, circular recess 55 slightly larger in diameter than the bore 41, and a beveled internal flange 56 is formed upon the wall of the bore 41 at the bottom of the recess 55. The rearward face of the projectile 48 has its edge beveled so as to be complementary to the beveled flange 56 to permit the projectile to seat against said flange. Thus, the flange limits the rearward movement of the projectile within the bore and prevents the projectile from being forced into the powder chamber 44 and damaging the contents thereof.

A booster charge 51, in the form of a relatively thin disk is positioned within the recess 55 so as to abut the rearward face of the projectile and to be exposed to the open end of the groove 56 carried by the projectile. A powder charge 58 is disposed within the powder chamber 54, and may .i

be of any desirable type or nature. There are a wide variety of propellant powders which may be used. in conjunction with this type of gun, and it is contemplated to encompass the use of any of the powder types. The charge 58 is in the form of a relatively short cylinder so as to have a snug fit within the chamber 44 and a tight engagement with one face of the booster charge 5'1. Ascrew-threaded plug 59 engages within the screw-threaded outer portion of the box 4| to retain the powder charge in place and to absorb the recoil forces exerted by the powder charge when the gun is fired. The plug 59 carries on its. outer end a polygonal recess adapted-to receive a suitable wrench of the Allen type (not shown) to permit unscrewing and removal of the plug. No portion of the plug 59 projects beyond the outer wall of the gunbody 35, so that no obstructions are presented to the passage of the gun through the well bore.

A circular soft metal sealing disk 62 is positioned in the bottom of the box 49 so as to abut the larger end of the tapered sleeve 46. The disk 62 is formed with a double tapered opening 63 in its central portion, the openingbeing substantially equal in diameter to the diameter of the bullet or projectile 48, and being closed by a beveled soft metal disk 64 seated or secured within the opening. The disk may be held in place by a suitable sealing compound or by brazing as is shown in Fig. 5 of the drawings, if desired. The disk 64 has its larger face directed outwardly toward the exterior of the gun body and is adapted to be carried with the projectile 48 in its trajectory to effect more eflicient perforation of thewell conductors, as will be more fully explained hereinafter. As is also shown in Fig. 5, the point or nose of the projectile may be secured to the disk 64 by embedding the nose therein and/or brazing the joint between the projectile and disk. In this mamier, the projectile and plate may be inserted in the gun element as a unitary body and extraneous movement of the projectile within the bore 41 is prevented.

An externally screw-threaded barrel 66 engages within the box 49 to retain the plate 62 in place and to provide barrel means for the travel of the projectile 48. The barrel is provided- With the usual bore 69 substantially equal in diameter to the bore 41, and has formed on its outer end a polygonal pin H surrounding the bore 69 and adapted to receive a suitable wrench for removal of the barrel. Obviously, removal of the barrel 66 allows removal of the plate 62 and the projectile 48 along with the tapered sleeve 48. Also, removal of the plug 59 allows removal of the powder charge 58 from the outer chamber 44, along with the booster charge 51, or the booster charge may be removed through the box 46.

A second gun element is shown in Fig. l as being disposed below the uppermost elements 39, and in vertical alinernent therewith. The second gun element is hsown as adapted to fire a projectile in the opposite direction to the uppermost element. As pointed out hereinbefore, any suitable number of gun elements may be incorporated into the gun body 35, and any desirable number of gun bodies may be suspended one from another. It is also pointed out, that the gun elements may face in any desired direction so that any desirable portion of the casing or conductor may be perforated, it being customary in perforating guns, to stagger the arrangement of the guns so that substantially uniformly placed perforations are obtained in the well conductor.

In the operation of this form of the invention, the gun is lowered into the well bore upon the cable H to the desired point hi the well bore where the perforation of the well, conductor is to be carried out. After positioning, the electrical circuit. is energized by suitable means (not shown), whereby an electric current is caused to flow in the electrical conductor [2, thereby detonating the electrically fired cap 25. The flame and burning gas-es created by the cap 25 travel downwardly through the bore 2 I, the box 38, and the bore 3?" into the. grooves 49 and 59. The flame is communicated from the grooves through the ports 5!, the grooves 52 and 53, and the groove 54 to the booster charge 5?, thereby detonating or exploding the latter. The explosion of the booster charge 51' sets off the main powder charge 58, which burns rapidly to propel the projectile 48 outwardly through the barrel 56. As the projectile commences its outwardtravel, the plate 64 is unseated or broken loose from the disk 62 and carried with theprojectile through the barrel 69 and into contact with the well casing. As the projectile contacts and penetrates the well casing, the soft metal plate 6&- is deformed into the con figurationof the nose portion of the projectile and flows rearwardly over said nose portion of the projectile to effect a Wiping action around the edges of the perforation in the casing. This ac tion effectively removes orprevents the formation 7 of upstanding burrs or other projections which might be formed by the projectile. Thus, the interior wall of the well conductor remains smooth and unobstructed after perforation.

This perforating gun is unusually safe to handle and to service by reason of the provision of the plug 59. If, for any reason, one of the gun elements does not fire, or the entire gun is removed from the well without firing, the gun elements may be unloaded from the rearward side by removing the plug 59 and the powder charge 44. The gun is then rendered safe and cannot fire accidentally. It is pointed out that this operation does not require exposure of the servicing personnel to the forward end of the gun element and injury of personnel by accidental discharge of the gun is minimized.

Should the travel of flame from the detonating cap be interrupted for any reason, the flame from an exploded powder charge would serve as a detonating flame, so that mis-fires are minimized.

A modification of the invention is shown in Figs. '7 through 10 of the drawings. This modification utilizes most of the structure described in connection with the first form of the invention, but is adapted for electrical firing of each gun element rather than the firing of a single electric cap with the resultant flame-propagated firing of the gun elements.

In the second form of the invention, the numeral 10 designates a head body similar to the head l3 and having a cable secured to its upper end. The head 10 is provided with a depending screw-threaded pin 12 on its lower end and an axial bore 13. The bore 13 is enlarged at the lower end of the head to form a recess 14 which is enlarged further by counterboring to form an annular space 15 beneath the recess '14 and a shoulder 16. An electrical conductor Tl, similar to the conductor l2, extends downwardly from the cable through the bore 13, terminating in a contact face 78 positioned within the recess 14 surrounded by a cup-like insulator 19 to prevent shorting of the contact 18 of the head 19.

A sub 80 is provided with a screw-threaded box 8| on its upper end, which box engages the pin 12 to secure the sub 80 to the head 10. A longitudinal bore 8|, relatively small in cross-section, extends throughout the length of the sub 90, and is enlarged at its upper end to form a screw-threaded box 82. A flanged insulating bushing 83 has engagement in the box 82 and is adapted to have its flange disposed within the counterbored portion 15 of the recess 14. The shoulder 16 engages the flange to form a snug joint. The bushing 83 is provided with an axial bore 84 substantially equal in diameter to the bore 8|, and an electrical conductor 85 extends through said bushing and through the bore 8|. A contact 88, similar to the contact 18, is recessed in the upper surface of the bushing 83 and is connected electrically to the upper end of the conductor 85. A recess 81, similar to the recess 14, is formed in the lower end of the sub 80, which is reduced and screw-threaded to form a screwthreaded pin 88, said recess being counterbored to form an enlarged portion 89 at the face of the recess 8'1. The lower end of the conductor 85 is electrically connected to a contact 98 positioned within the recess 81 and surrounded by a cuplike insulating member 9|.

A gun body 92, similar in most respects to the gun body 35, is formed with a screw-threaded box 93 on its upper end so as to engage the pin 88 of the sub 80. A passage 93 extends longitudinally of the gun body 92, being substantially equal in diameter to the bores 13 and 8|, and being enlarged at its upper end to form a screwthreaded box 94. A bushing is disposed within the box 94 and carries a contact 98 in the same manner as the bushing 83 carries the contact 86. An electrical conductor 91 is disposed within the passage 93 and is connected electrically to the contact 96.

The lower end of the gun body 92 is reduced and screw-threaded to form a pin and a second gun body 92, similar to the gun body 92, depends from the pin.

A gun element 98 similar in nearly all respects to the gun element 39, is disposed transversely of the gun body 92 below the upper end thereof. As was pointed out in connection with the first form of this invention, any desirable number of the gun elements may be disposed within the gun body 92, although only two such bodies are shown, and any desirable number of gun bodies may be utilized. The only difierence in structure is the inclusion of electrical conducting means within the gun element to conduct electric current to the electrical firing cap, which will be described hereinafter.

A circular electrical conductor 99 is disposed within the space enclosed within the grooves 49 and 5D, the conductor being insulated from the gun body and from the tapered sleeve 46 with the exception of points exposed to the bore 93 on the outside of the conductor, and one point on the inside of the conductor overlying the port 5|, only one of which is provided in this modification. The conductor 9'! has its lower end exposed and in contact with the exposed portion of the conductor 99 upon the upper side of the sleeve 46, while a similar conductor I09 extending downwardly through the bore 93 below the uppermost gun element has its upper end exposed and in contact with the exposed portion of the conductor 99 on the lower side of the sleeve 45. Thus, electric current may pass through the conductor 91 to the circular conductor 99 and thence to the conductor |99 and so on down the body of the gun to each of the gun elements being utilized.

An electrical detonating cap |9| is disposed within the port 5| and has its base portion contacting the exposed part of the conductor 99 which overlies the port 5|. Electric current is thus conducted to the cap by means of the circular conductor 99 so as to detonate the cap, when desired, and fire the gun. It is pointed out, that the circular conductor 99 is split at I82 diametrically opposite the cap ||l| to allow the positioning of the conductor around the tapered sleeve 46.

In the operation of this modification of the invention, an electric current is passed down the conductor 73 within the cable 1| and is transmitted through the various contact points to the conductor 99, resulting in the firing of the cap |9|. The flame and burning gases produced by the cap |U| pass through the port 5| to the grooves 52 and 53, and the groove 54 to the booster charge 5?, detonating the charge 51 and thereby the main powder charge 59. The operation of the gun from this point onward is the same as that of the first form described.

This modified form of the invention provides the same safety features and efiicient well conductor perforating means as the first form.

In Fig. 11 of the drawings is shown another a similar screw-threaded box H5.

9 modification of the invention. This latter modification may be utilized with any of the preceding forms described and provides additional safeguards for operating personnel. The projectilecarry ing sleeve as well as the powder charge may U be removed from a specific gun element without necessitating exposure of the operator to the muzzle of the gun.

In this form, the numeral H designates a cylindrical gun body, similar to the gun bodies 35 and 92. The body H0 is provided with a transverse, diametric bore I II having its central portion H2 tapered. The bore is adapted to receive a gun element II'3 similar to the previously described elements. The larger end of the tapered central portion H2 of the bore III is directed toward the rearward side of the gun and un element. The rearward end of the bore is enlarged to form a screw-threaded box H4, and the forward end of the bore is enlarged to form A suitable screw-threaded plug H6 engages within the box H4 and a sealing disk I ll, similar to the disk 62, is held within the box H5 by a screwthreaded barrel IE8, similar to the barrel B6.

.A -tapered or conical sleeve H9 is disposed within the bore I I2 and abuts the rearwardor lower side of the disk III. A projectile I is carried within the bore I 2I of the sleeve, the barrel II8 having an alined bore I22. The gun body H0 and sleeve H9 are provided with matching circular grooves I23, similar to the grooves 49 and 50, while the sleeve carries radial ports I24 and internal grooves I and I25, similar to the ports 5! and the grooves 52 and 50' respectively, which were previously described. The projectile I26 is similar in all respects to the projectile t5, carrying the circular and longitudinal grooves described and having a booster charge I26 abutting its rearward face.

The rearward portion of the tapered bore H2 forms a powder chamber and receives a tapered or conical liner I21 which functions to hold the sleeve H9 in place and to contain a powder charge I28. The plug IIB engages the rearward edge of the liner to secure the liner and the sleeve in place within the tapered bore, and at the same time holds the powder charge in place.

Obviously, an operator of the gun may unscrew the plug IIS, and thereby remove the powder charge and the tapered sleeve along with the projectile without exposing himself to the muzzle of the gun. The gun elements are normally arranged in staggered or spiral relation, but by beginning at one end of 'the gun and working toward the other, while keeping his body to one side of the adjacent gun elements, the operator may completely unload the gun without endangering his person.

In Fig. 12 a further modification is shown which allows removal of the gun barrel from the rearward side of the gun. This form is similar to the form shown in Fig. 11 except that the barrel H8 is not used. The box H5 is replaced with a tapered bore I33. The rearward, larger end of the bore I30 is less in diameter than the forward, smaller end of the bore H2 so as to form an annular shoulder I3I against which the sealing disk II'I seats. A tapered or conical barrel I32 is positioned within the bore I35 and held therein by the disk. The barrel is provided with a cylindrical bore I33 in alinement with the bore I2I of the sleeve H3. As shown, the remaining elements of this form are the same as the similar elements described in the revious 1-0 form and have been assigned the same numerals.

The provision of the tapered barrel prevents loss of the barrel in the well bore after firing of the gun. It is a relatively common occurrence for a screw-threaded barrel to become loosened after firing so as to project slightly from the gun body. In raising the body body to the surface, the gun barrels are rubbed against the well conductor, further loosening the barrels until they are entirely free. The barrels then often become wedged between the gun body and the inside wall of the well conductor resulting in a stuck perforating gun. Such an occurrence necessitates an expensive fishing job and holds up operations on the well.

With the present invention, the barrel cannot become loose and fall out of the gun body "due to its tapered or conical construction. A definite advantage is thus achieved.

. By removing the plug H6 in this modification, all the movable elements of the gun may be removed from the gun body, including the sealing disk and the barrel. The same safety features as pointed out hereinbefore obtain.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the inven tion.

What I claim and desire to secure by Letters Paten-t'is:

1. A well casing perforating .gun including, a gun body adapted to be lowered in a well bore, firing impulse conducting means extending axially of the body, means for suspending additional gun bodies from the uppermost body, each gun body having impulse conducting means extending axially thereof and intersecting a plurality of bores extending transversely of the bodies, a tapered sleeve disposed within each bore in vertical alinement with the conducting means, said sleeve having an annular groove about its circumference, the bodies having a mating groove formed in each of the bores, said grooves registering with the conducting means to make provision for conducting a firing impulse around the sleeve and to a lower sleeve, ports in the sleeves for conducting a firing impulse to the interior thereof, a projectile disposed within the sleeve, said projectile having an annular groove and a longitudinal groove for conducting a firing impulse to the rearward portion of the bore, a powder charge disposed within said rearward portion of the bore, a removable plug for holding said charge in place, and a removable barrel positioned in the forward end of the bore for holding the sleeve in place.

2. A well casing perforating gun as set out in claim 1, and a plate disposed between the sleeve and the barrel, said plate having a central opening therein and a beveled disk disposed in said opening, said disk being adapted to be separated from the plate by the projectile in its trajectory.

3. A well casin perforating gun including, a gun body adapted to be lowered into a well bore. a plurality of gun elements extending transversely of the gun body, an arcuate electrical conductor encircling each gun element, an electrical conductor extending above and between each of the gun elements and in contact with the arcuate conductors, a firing cap carried by each gun element and connected to the arcuate conductor, a powder charge in each gun element, and means 11 for conducting the firing impulse of the cap within the element to the firing charge.

4. A well casing perforating gun including, a gun body adapted to be lowered in a well bore and having a transverse bore, a gun element carried by the gun body and including, a projectilecarrying conical sleeve disposed within the bor a barrel secured in one end of the bore, and a retaining element secured in the other end of the bore.

5. A well casing perforating gun including, a gun body adapted to be lowered in a well bore and having a transverse bore, a gun element carried by the gun body and including, a projectilecarryin conical sleeve disposed within the bore, a conical barrel secured in one end of the bore, and a retaining element secured in the other end of the bore.

6. A well casing perforating gun including, a gun body having a transverse bore, said bore being adapted to receive a gun element and being tapered so as to have its smaller end toward the muzzle of the gun element, a conical sleeve within the bore, a projectile within the sleeve, a conical powder chamber liner abutting the sleeve, a barrel secured in one end of the bore, and a retaining element secured in the other end of the bore.

7. A well casing perforating gun including, a gun body having a transverse bore, said bore being adapted to receive a gun element and being tapered so as to hav its smaller end toward the muzzle of the gun element, a conical sleeve within the bore, a projectile within the sleeve, a conical powder chamber liner abutting the sleeve, a

conical barrel disposed in one end of the bore, and a retaining element secured in the other end of the bore.

8. A well casing perforating gun including, a gun body adapted to be lowered into a well casing, a flame conduit extending axially of the body, and a plurality of gun elements carried by the body, each element having a member for carrying a bullet bisecting said conduit, a powder-charge chamber adjacent said member and ofiset from said conduit, flame producing means connected with the conduit, and a check in the conduit between the flame producing means and the first gun element responsive to a back pressure in said conduit.

WILMERTH R. ATWOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,376,530 Greener May 3, 1921 1,624,649 DesAllimes Apr. 12, 1927 2,041,209 Ridley May 19, 1936 2,232,634 Roberts Feb. 18, 1941 2,250,055 Alexander July 22, 1941 2,292,670 Smith Aug. 11, 1942 2,295,634 Collins Sept. 15, 1942 2,351,179 Aloi June 13, 1944 2,407,081 Johnston Sept. 3, 1946 2,439,643 Atwood Apr. 13, 1948 2,456,977 McCullough Dec. 21, 1948 

